diff --git a/hw/char/serial.c b/hw/char/serial.c
index 6d3b5aff8b1ca66e3326c48f5f73e58dab38162a..f4d167f9167070672ffd1f21110c830e55fdf316 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -225,8 +225,10 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque)
 
     if (s->tsr_retry <= 0) {
         if (s->fcr & UART_FCR_FE) {
-            s->tsr = fifo8_is_empty(&s->xmit_fifo) ?
-                        0 : fifo8_pop(&s->xmit_fifo);
+            if (fifo8_is_empty(&s->xmit_fifo)) {
+                return FALSE;
+            }
+            s->tsr = fifo8_pop(&s->xmit_fifo);
             if (!s->xmit_fifo.num) {
                 s->lsr |= UART_LSR_THRE;
             }